Processing of pellet-shaped articles, e.g., pharmaceuticals such as caplets and tablets, confections (e.g., lentil shaped coated chocolate candies), edible and non-edible articles, etc., is known in the art. Processing operations typically include marking the articles with indicia (e.g., logos, multi-color designs, alpha-numeric, etc.), laser drilling the articles and/or coating the articles. Processing operations are often performed in a sequential manner wherein articles are conveyed past a first processing unit that performs a first processing operation and then past a second processing unit, downstream from the first processing unit, that performs a second processing operation.
Such processing becomes more complicated when the articles are fed in random order to a conveyer and only one of the sides of the pellet-shaped articles is to receive processing. U.S. Pat. No. 5,894,801 to Ackley, incorporated herein by reference in its entirety, discloses a processing and inspection unit in which the articles are monitored and selected ones of the articles which have the wrong side up are flipped such that all of the articles have a common side exposed before processing takes place on the correctly exposed sides. The above process can be useful, for example, if each of the articles is to be laser drilled on only one side but not the other. Article processing becomes even more complicated if both sides of the article are intended to receive different processes, e.g., laser drilling on one side, and printing on the other side.
Where the articles are to be marked with identifying indicia, such as a product name or logo, such marks can be made in several ways. However, predominant is the use of contact printers, such as an offset rotogravure printing unit that includes an ink roll and a design roll. However, contact printers require a new design roll for each new logo, and due to contact between the roll and the article, the positioning of the articles can be upset. Non-contact printers such as ink-jet printers have also been used, but these may be associated with clogging and insufficient drying time between operations if multiple operations, e.g., multiple colors, are to be serially registered.
Other non-contact printers include the use of a laser to etch a logo, such as disclosed in WO 91/01884, which is directed to a two-step branding apparatus in which a printer 35 prints a solid rectangular block which is then subsequently subjected to a laser etching step, whereby portions of the ink coating just applied by the printer 35 are removed to define a desired symbol and/or alphabetic and/or numeric characters, such as “MOTRIN”. However, the laser is conventional in that it uses a mask in order to create markings on the pellet shaped articles.
Therefore, a need has developed in the art to address the drawbacks and/or inadequacies of the systems described above.